What happened
On 25 January 2010, Ethiopian Airlines flight ET 409, a Boeing 737-800 registered ET-ANB, departed Beirut Rafic Hariri International Airport for Addis Ababa. Shortly after takeoff, the aircraft was instructed by Air Traffic Control to perform a right turn to a heading of 315°. During the maneuver, the aircraft continued turning beyond the selected heading.
As the aircraft attempted to correct its course by turning left to a heading of 270°, it overbanked significantly. The aircraft entered a series of stalls and a subsequent spiral dive. The flight ended when the aircraft impacted the Mediterranean Sea approximately 5 nautical miles southwest of the airport, roughly five minutes after the start of the takeoff roll. All 90 persons on board, including 82 passengers and 8 crew members, were fatally injured.
The investigation
The investigation, conducted by the Lebanese Investigation Committee, examined the flight' and aircraft data using the Digital Flight Data Recorder (DFDR) and Cockpit Voice Recorder (CVR). Investigators analyzed the aircraft's flight path via radar data and performed simulations using the M-Cab flight simulator. The team also conducted a technical analysis of the aircraft's trim-tab system and investigated the presence of black soot near the APU exhaust. The investigation reviewed the airline's operational procedures, crew training, and the meteorological conditions, which included low clouds and thunderstorms in the area.